@Rojo Lewis  It depends a lot on your relationship, but here are my thoughts as we approach our 40th wedding anniversary in September.  

Offer deals for celebration of Spring and Fall birthdays or anniversaries too. 

Yesterday was my anniversary.

I arrived at my cabin in Pigeon Forge yesterday to find that my housekeeper had removed my high quality towels and sheets and replaced them with cheap alternatives and had never stocked my house with items (coffee, olive oil, hand soap...)

At my rental, I left a new roll of paper towels, a bottle of Windex, a new bottle of hand dish soap, a new bottle of hand soap, a 4-pack of toilet paper, and a pack of clothes hangers in the house for move-in day. 

Dishes, utensils, bed/bath linens, soaps, garbage bags, etc.  

No soap scum, cracks, nothing of that sorts, then she was repeating about the toilet and about the paint on the outside of the mobile home being half done which my 65 year old husband has not had the time to finish just yet.

He has a solid concept built around "anniversaries" (not renewals!)

(I just celebrated our 40th anniversary with my charming and vivacious wife.)

On the 50th anniversary of the Apollo 11's moon landing, the website is selling plots 10 miles from the landing site.https://www.edgeprop.sg/property-news/priced-out-most-expensive-real-estate-market-earth-get-acre-lunar-property-us2499